Improve 'my head exploded' error message

diff --git a/compiler/typecheck/TcPat.lhs b/compiler/typecheck/TcPat.lhs
index 4d5aaf6..a8e2d39 100644 (file)
--- a/compiler/typecheck/TcPat.lhs
+++ b/compiler/typecheck/TcPat.lhs
@@ -920,6 +920,7 @@ patCtxt pat             = Just (hang (ptext SLIT("In the pattern:"))
 existentialExplode pat
   = hang (vcat [text "My brain just exploded.",
                text "I can't handle pattern bindings for existentially-quantified constructors.",
+               text "Instead, use a case-expression to unpack the constructor.",
                text "In the binding group for"])
        4 (ppr pat)